(1) Field of the Invention
The present invention relates to folding cartons and in particular folding cartons that are cut from a sheet of carton material in mutually confronting arrangement that conserves material, and that are quickly folded from a flat configuration to a rectangular box configuration with a reinforced bottom wall that is pressed into the rectangular box configuration and locked in position at the bottom of the box without gluing.
The invention pertains to and is an improvement over cartons of the type disclosed in U.S. Pat. No. 3,731,873.
(2) Description of the Related Art
The U.S. Pat. No. 3,731,873 discloses the type of folding carton to which the present invention pertains. This prior art carton comprises four rectangular wall sections connected end-to-end with fold lines scored between adjacent wall sections. A tab is provided at one end of the wall sections and is arranged to be glued to the wall section at the opposite end of the connected wall sections to enable the walls to be formed into the rectangular box configuration.
Each wall section has a wall reinforcement flap connected along its top edge. The reinforcement flap is arranged to be folded over a fold line between the top edge of the wall section and the reinforcement flap, and to be glued to the inside surface of the wall section. When the four wall sections are folded into their rectangular box configuration, three of the wall reinforcement flaps glued to the inside surface of the wall sections form two locking ledges overhanging the interior surfaces of two of the wall sections, and a cutout ledge overhanging a fraction of the interior surface of a third wall section.
One of the four carton wall sections is connected to a carton bottom along a fold line at the bottom of the wall section, and the remaining wall sections are connected to bottom supports along fold lines at the bottom of the wall sections. The carton bottom is adapted to be folded into the rectangular box configuration formed by the folded wall sections and supported by the three bottom supports at the bottom of the box. The carton bottom is locked in place by first and second side flanges extending along first and second edges of the carton bottom, and a tab that extends along a portion of a third edge of the carton bottom. With the carton bottom positioned at the bottom of the box, the first and second side flanges extend along and engage with the two overhanging locking ledges formed by the reinforcement flaps glued to the interior surfaces of the wall sections, and the tab engages with the cutout ledge formed by the reinforcement flap glued to the third wall section. The engagement of the side flanges and the tab with the reinforcement flaps locks the carton bottom in position and prevents it from being pushed up into the rectangular box configuration formed by the wall sections of the folded carton. The bottom supports prevent the carton bottom from being pushed down, out of the rectangular box configuration formed by the wall sections of the folded carton.
This prior art folding carton has disadvantages that are due to the manner in which the folding carton is cut from the blank sheet of carton material. The wall reinforcement flaps of the carton provide an overhanging locking ledge across only two of the side walls and only a small, cutout overhanging ledge across a portion of the third side wall. The bottom side flanges extend completely across only two sides of the carton bottom. These side flanges engage with the two locking ledges of the wall reinforcement flaps and also provide reinforcement against bending to two sides of the carton bottom. The tab on the third side of the carton bottom only locks that side in place and does not provide reinforcement to the bottom section to prevent bending as do the two side flanges.
Also, the production of the prior art container wastes a substantial amount of carton material. The outline of the prior art container permits only a partial nesting of the two carton outlines. The two cartons confront each other along only a limited portion of their outlines, leaving a substantial amount of the carton material remaining between the two carton outlines that is discarded as waste after the carton has been cut.
The present invention overcomes the above-cited shortcomings of the prior art folding carton by providing a carton that comprises reinforcing flaps adhered to the interior surfaces of the four carton wall sections and presenting three overhanging locking ledges across the entire surfaces of three of the wall sections. The bottom of the carton of the present invention comprises three strengthening flanges that extend along the entire lengths of three sides of the carton bottom and prevent bending of the carton bottom. The three strengthening flanges also engage with the three overhanging locking ledges to hold the bottom of the carton in place at the bottom of the rectangular box configuration formed from the carton wall sections.
A second embodiment of the invention also comprises three strengthening flanges that extend along the entire lengths of three sides of the carton bottom and prevent bending of the carton bottom. Portions of the three strengthening flanges of the second embodiment engage in slots in three of the cartons wall sections to hold the bottom of the carton in place at the bottom of the rectangular box configuration formed from the carton wall sections.
The outline of the folding carton of the present invention enables two cartons to mutually confront each other and be cut from the same rectangular area of carton material, resulting in a more efficient use of the carton material than in the prior art folding cartons.
It is therefore an object of the present invention to provide a folding carton with an improved strengthening flange arrangement that provides additional support against bending to the carton bottom while locking the bottom in place when the carton is folded into a rectangular box configuration, and also provides a carton outline dimensioned to mutually confront a second carton and enable the two folding cartons to be cut from the same rectangular area of carton material.